582 SAMUEL CALVIN 



which the names Kansan and Iowan should be applied. On the 

 other hand, the original descriptions of the lower and upper till — 

 of the Kansan and the Iowan — must have careful consideration, 

 and the evidence of the map in The Great Ice Age, above cited, 

 must be taken into account. The descriptions would have to be 

 rewritten and the map redrawn to make them consistent with the 

 view that the Kansan is sub-Aftonian. If the term Kansan is 

 transferred to the sub-Aftonian, and the term Iowan to the drift 

 next above, 1 practically the whole area represented on the map as 

 Kansan would have to be changed to Iowan. The Iowan would 

 then extend into southern Illinois, would cover southern and western 

 Iowa, northern Missouri, eastern Nebraska, and northeastern 

 Kansas. With the transfer of the term to the sub-Aftonian the 

 Kansan would be represented on the map by a few dots and thin 

 lines that could be seen only with the magnifier, the whole area 

 comprising an aggregate of only a few sections; and in the present 

 state of knowledge we could not be certain that Kansas has a cubic 

 foot of Kansan (sub-Aftonian) drift. We are face to face with the 

 fact that any application of the terms Kansan and Iowan involves 

 some inconsistencies, is at variance with some of the statements 

 in the original publications; and so long as we seem to need the 

 terms and have to use them, it is only a question of how to use and 

 apply them so as to do least violence to the original maps and 

 descriptions. If the map and descriptive texts referred to may be 

 taken as representing the intent of the authors, the practice of 

 applying the terms which has been followed, and which seems now 

 to come in for a certain amount of mild condemnation, is the only 

 one that is reasonably consistent or possible. For it must be 

 admitted that if the sub-Aftonian is to be called Kansan, and the 

 first super- Aftonian drift is to be the Iowan, more than nine-tenths 

 of the original descriptions are wholly erroneous and misleading, 

 and the map in The Great Ice Age showing the distribution of these 

 drifts is altogether meaningless and at variance with the facts. 

 Recent usage in the application of the terms Kansan and Iowan is 

 based on what seemed to be, and still seems to be, the only reason- 



1 Some such shift as this seems to be favored by what is said in the Journal of 

 Geology, July-August, 1910, pp. 473-74. 



